Hanau S, Rippa M, Bertelli M, Dallocchio F, Barrett M P
Dipartimento di Biochimica e Biologia molecolare, Università di Ferrara, Italy.
Eur J Biochem. 1996 Sep 15;240(3):592-9. doi: 10.1111/j.1432-1033.1996.0592h.x.
The kinetics of 6-phosphogluconate dehydrogenase from Trypanosoma brucei was examined and compared to those of the same enzyme from lamb's liver. Variation of kinetic parameters as a function of pH suggests a chemical mechanism similar to other 6-phosphogluconate dehydrogenases. The comparison extended to a detailed analysis of the effect on enzyme activity by several inhibitors including the trypanocidal drugs suramin, melarsoprol and analogues of these compounds. The T. brucei enzyme differs significantly from its mammalian counterpart with respect to several inhibitors, particularly the substrate analogue 6-phospho-2-deoxygluconate and the coenzyme analogue adenosine 2',5'-bisphosphate which have respectively 170-fold and 40-fold higher affinity for the parasite enzyme.
对布氏锥虫的6-磷酸葡萄糖酸脱氢酶的动力学进行了研究,并与羊肝中同一酶的动力学进行了比较。动力学参数随pH值的变化表明其化学机制与其他6-磷酸葡萄糖酸脱氢酶相似。该比较还扩展到对几种抑制剂对酶活性影响的详细分析,这些抑制剂包括杀锥虫药物苏拉明、美拉胂醇以及这些化合物的类似物。布氏锥虫的这种酶在对几种抑制剂的反应上与其哺乳动物对应物有显著差异,特别是底物类似物6-磷酸-2-脱氧葡萄糖酸和辅酶类似物腺苷2',5'-二磷酸,它们对寄生虫酶的亲和力分别比其高170倍和40倍。